Ice flake machines



March 24, 1970 J. E. WADSACK 3,501,927

ICE FLAKE MACHINES 2 s 'ts-sheet 1 Filed July 29, 1968 l I l I 1 I I I l a l l I I I I I FIG. I

FIG. 3

INVENTOR. Joe E. Wadsack I BY 1 ATTORNEYS March 24, 1970 i J. E. WADSACK 3,501,927

ICEYFLAKE MACHINES Filed July 29, 1968 2 Sheets-Sheet 2 I m ll! I FIG. 7

INVENTOR. Joe E. Wadsack FIG. 6 BY ATTORNEYS United States Patent 3,501,927 ICE FLAKE MACHINES Joe E. Wadsack, Denver, Colo., assignor to Mile High Equipment Company, Denver, Colo., a corporation of Colorado Filed July 29, 1968, Ser. No. 748,273 Int. Cl. F25c 1/14 US. Cl. 62-320 7 Claims ABSTRACT OF THE DISCLOSURE A flake ice machine of the type which provides an auger to scrape ice layers from the walls of a refrigerated cylinder, to move the layers upwardly in the cylinder and compress them against an abutment at the top of the cylinder whereby to congeal the same into a tubular ice column, and to discharge the column as ice chips from an opening in the side of the cylinder above the auger by breaking up the tubular column and below a bearing housing closing the top end of the cylinder. The underside of the bearing housing forms the abutment shoulder against which the ice is compressed. To prevent ice from freezing within the cylinder and jamming the machine, it was found that the machines could be proportioned by selecting a height H of the opening, a thickness T of the tubular ice column and the diameter D of the cylinder in such a manner as to produce a relationship in units of inches, which is greater than 11.0.

The present invention relates to improvements in the manufacture of ice chips commonly referred to in the industry as flake ice, and more particularly to the machines for the manufacture of flake ice which use an anger to scrape thin layers of ice from the walls of a waterfllled, upright, refrigerated cylinder.

In the type of machines herein considered rotation of the auger directs the layers of ice into a chamber portion of the cylinder above the auger and against an abutment closing the top of the chamber. There the layers are compressed into ice chips, or flakes, and these ice chips are discharged from an opening in the side of the chamber portion.

The prior art of manufacturing flake ice by using an anger to scrape ice from the walls of an upright, refrigerated cylinder and to eject the same from an opening at the side of a chamber portion of the cylinder above the anger is exemplified by the constructions shown in the Patents: 2,753,694 issued July 10, 1956 to Trow et al.; 3,002,361 issued Oct. 3, 1961 to Whetstone; 3,162,022 issued Dec. 22, 1964 to Relph et al.; and 3,197,974 issued Aug. 3, 1965 to Smith et al. of which applicant is a coinventor.

All of the prior art constructions close the top of the cylinder with a bearing housing which holds one end of the auger shaft, and the abutment against which the ice layers are compressed is the undersurface of this bearing housing. All of these prior art constructions include a means within the top of the cylinder which deflects and directs the ice chips from the opening in the chamber at the top of the cylinder, or assists in the ice chips being discharged from the opening.

The Trow et al. construction uses an open chamber and the deflector is formed as an inclined and curved undersurface of the bearing housing. Whetstone uses an inverted, conical surface. Relph discloses a flat shoulder on the underside of the bearing housing, but with a cylindrical projection depending from the housing within the chamber. This projection carries a deflector adjacent 3,501,927 Patented Mar. 24, 1970 to the opening. Smith, et al. discloses a flat shoulder similar to that of Relph, but includes a knob, indicated as indentation 55 in that patent, within the chamber on the cylinder wall, which stops the rotation of ice in the chamber to assist discharge of the ice from the opening.

In all of these constructions, the deflector or other means were considered essential to successful operation of the ice machine, for without the same it was generally recognized that such machines would either not make flake ice or they would jam if the deflector or other means were omitted. This jamming action was noted in the Smith et al. patent which states at col. 5, line 67 to col.,'6, line 2: continued upward movement of this tubular column of soft ice brought the column to the ceiling 54 (the bearing housing abutment) and thereafter the column was compressed by the action of the rotating spiral (the auger). Without means for deflecting this column of soft ice out of the chamber, it tended to rotate with rotation of the spiral (the auger) and the compression increased as more ice formed below it and finally to the point where the column of ice solidified. Thereafter, the pressure built up by rotation of the spiral to the point where the apparatus either jams or breaks The statement in the Smith et al. patent was corroborated by Dr. William Colburn, who testified and demonstrated as an expert witness in numerous litigations involving the Trow et al. patent, that if the deflector or other means were removed from an ice machine of this type, so that the ice layers would be projected and compressed against a flat abutment, normal to the axis of a cylinder, the machine would jam and become inoperative.

The present invention was conceived and developed with these considerationsin view, with a primary object of improving the quality of the flake ice produced in a flake ice machine. Not only is the flake ice discharged from a conventional machine, having a deflector means in the chamber, somewhat soft and slushy, but also the quality of the ice will vary significantly with variations inthe type of water being used and in ambient conditions under which the machines are used. It had been observed that whenever one of these machines had the deflector means removed so that the ice would be compressed against the flat undersurface of a bearing housing, the ice would be ejected from the machine for a short period of time before it froze and jammed. However, just before the machine froze and jammed, the ice would become much harder and drier and of a more desirable quality than flake ice produced in a commercial machine having the deflector means present.

The present invention comprises, in essence, a flake ice machine of the type considered, having no deflector means within the chamber, but only a flat abutment at the undersurface of the bearing housing against which the ice is compressed before being ejected from the opening at the side thereof. The present invention was based upon the discovery that an improved and operative flake ice machine could be built in this manner by modifying the proportions of the auger and outlet, and it was discovered that certain dimensions of the auger and opening could be selectively proportioned according to a simple ratio to provide criterion for designing a successful, continuously operating flake ice machine.

Another object of the invention is to provide a novel and improved construction of a flake ice machine which functions to produce hard, solid chips of ice by the formation of a substantially solid ice column and buckling this column at the opening to break the same up into chips.

Another object of the invention is to provide a novel and improved ice flake machine of a simplified and economical construction by the elimination of a deflecting means within the cylinder.

Another object of the invention is to provide a novel and improved flake ice machine which operates upon the principle of buckling a column of substantially solid ice out of the chamber opening to break the same into chips and which will operate in a reliable manner to produce hard, dry flake ice regardless of the type of water used, the ambient temperature, pressure and humidity to which the ice flake machine may be subjected.

Further objects of the invention are to provide a novel and improved flake ice machine which can produce a comparatively hard, solid chip and at the same time, significantly reduce the load upon the auger as it rotates to scrape and deflect ice from the cylinder.

With the foregoing and other objects in view, my invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated in the accompanying drawing in which:

FIGURE 1 is a perspective view of an ice chip producing machine of a type which includes the invention, but with cover plates forming the housing of the apparatus being removed to better show the components therewithin.

FIGURE 2 is a sectional, elevational view of the improved freezing cylinder and ice flake producing unit of the invention, as taken from the indicated line 22 at FIG. 1, but on an enlarged scale.

FIGURE 3 is a perspective, somewhat diagrammatic view of the upper portion of the freezing cylinder, with portions broken away to show constructions otherwise hidden from view.

FIGURE 4 is a sectional view as taken from the indicated line 44 at FIG. 2, but on an enlarged scale.

FIGURE 5 is a fragmentary sectional view, as taken from the indicated line 5-5 at FIG. 4.

FIGURE 6 is a diagrammatic view of a fragment of the outlet chamber illustrating a segment of an ice column at the outlet window thereof which is typical during the operation of the apparatus.

FIGURE 7 is a diagrammatic view similar to FIG. 6, but showing the manner in which the ice segment buckles by compressive action to be discharged from the outlet.

Referring more particularly to the drawing, FIGS. 1 and 2 illustrate a conventional organization of the components of a flake ice machine which forms the environment for the present invention. The flake ice machine is carried within and supported upon a box-like framework 10 which, in turn, is mounted within a suitable shell or bin, not shown. The components of the machine include a refrigeration apparatus R and the ice flake producing apparatus P wherein the improvements constituting the present invention are located.

The refrigeration apparatus R, shown at FIG. 1, is completely conventional. The refrigerating circuit includes a motor-compressor 11 which compresses refrigerant gas into a hot gas line 12 which enters the top of a condenser 13. The condenser is cooled by a fan or other means to liquify the gas and the liquid flows from the condenser through a line 14. This line extends from the condenser and to the ice flake apparatus P, and this line includes a drier 15 and an expansion valve 16. This expansion valve 16 is connected to the freezer-evaporator 17 of the ice flake apparatus P which is shown at FIG. 2 and surrounded by insulation 18 of FIG. 1. The cold refrigerant gas flows from this evaporator 17 into an overflow chamber, not shown, and thence into a return line 19 to the motor-compressor 11. The apparatus also includes suitable safety temperature and cut-off controls which may be conveniently mounted upon a control board 20.

The ice flake producing apparatus P includes a cylindrical body shell 21 which is mounted upon a suitable bracket 22 attached to a frame member 10. This cylinder 21 may be described as forming two contrasting sections, one being a lower freezing section F which extends over a. substantial portion of the cylinder and which is embraced by the evaporator 17. The other is an upper chamher C, having an opening in the sidewall through which ice is discharged. The lower end of the freezing section F is closed by a sealing means so that it may be filled with water. A water supply line 23 taps into this cylinder near its base.To regulate the water inflow and to hold the water within the cylinder at a level near the top of the freezing section, this supply line 23 extends upwardly alongside the shell to a water level chamber 24 having a float valve therein. Thence, a water line 23 extends to and is connected with a suitable water supply source, not shown.

A comparatively heavy, axially centered shaft 26 extends through this cylinder 21 and is formed with an enlarged central portion at the freezing section F to carry an anger flight, as hereinafter described. Each end of the shaft is reduced in diameter and is mounted in rigidly supported bearings 27. The bearings, in turn, are mounted within suitable sockets in an upper bearing housing 28 and a lower housing 29. The housings snugly fit into their respective ends of the cylinder 21 and each is provided with an outward shoulder 30 at its outer end which abuts against an end of the shell. Lock rings 31 are threaded over each end of the cylinder and over the bearing housing shoulders 30 to secure the assembly of components within the cylinder, each lock ring 31 including an inward, annular flange 32 for this purpose. A closure cap 33 is proportioned to rest upon the shoulder 30 of the upper bearing housing and this cap is also held in place by the lock ring flange 32.

The reduced-diameter, lower end of the shaft 26 projects below the cylinder 21 through the bearing housing 29 as a stub 34 which connects with a coupling 35 of a driving mechanism. The drive mechanism includes a speed reducer 36 having its slow speed output shaft carrying the coupling 35. A suitable motor 37 is connected with the input shaft of the speed reducer by a pulley-belt arrangement, not shown. These drive components, which are adapted to rotate the shaft 26 at a selected, slow speed, are mounted upon suitable plates 39 carried upon the framework 10 as illustrated.

A cylindrical space 40, an annulus in cross section, is formed within the freezing section F of the cylinder 21, between the inner wall of this cylinder 21 and the wall of an enlarged diameter section 41 of the auger shaft and carries an anger flight 42 as heretofore mentioned. The auger flight 42, which outstands from the enlarged section 41 of the auger shaft, snugly fits within the cylinder 21, in the annulus 40, and is adapted to scrape layers of ice as it is formed on the inner wall of the cylinder 21 as the shaft rotates. The upward wind of the auger flight is opposite to the direction of rotation of the shaft and this produces an upward movement of the ice particles as they are scraped off the cylinder wall.

The bottom of the annulus 40 is rendered watertight by suitable seals at the bearing housing 29. One seal is located between the cylinder 21 and the lower bearing housing and is preferably an O-ring 43 carried within a groove 44 at the outer face of the bearing housing. A short, tubular seal ring 45 is snugly fitted in the bearing housing 29 to upstand thereabove with its upper edge abutting against an anti-friction washer 46 which, in turn, tightly fits upon the shaft 26 at the lower end of the auger shaft section 41 as illustrated at FIG. 2.

The auger flight 42 does not extend into the chamber C, but terminates at the base thereof. Nevertheless, it will force the ice layers scraped from the freezing section F upwardly and into the chamber where they are compressed to form a tubular cylinder of ice which subsequently is broken into chips or flakes which are ejected from the chamber through an opening, all as hereinafter set forth.

The top of the chamber C, the freezing section, is closed by the upper bearing housing 28. While the enlarged auger shaft portion 41 terminates at the end of the auger flight or a short distance thereabove, a reduced diameter extension 26' of the auger shaft is within a cylindrical stub 47 depending from the upper bearing housing 28. The stub 47 is of the same outside diameter as the auger shaft portion 41, and the two components, i.e. the auger shaft 41 and the stub 47, form a columnlike structure extending through the cylinder 21 and continuing the annulus space 40 into the chamber C. Accordingly, this extension 47 snugly embraces the shaft portion 26' and abuts against the end of the auger root portion of the shaft. A water seal is provided between the smaller shaft portion 26' and the bearing housing extension 47, as "by an O-ring 48 carried in an annular groove 49 at the inner wall of the extension 47.

To complete this arrangement of the ice chip producing apparatus P, a rectangular outlet 50 is formed in the Wall of the cylinder 21 at the chamber and a disposal chute 51 outstands from this cylinder at the opening to direct ice formed within the unit and discharged therefrom to a suitable bin or container a short distance away from the cylinder 21. It is to be noted that this chute is preferably upwardly inclined with its floor 52 being flush with the lower edge of the opening 50 to facilitate the return of any water which may drain from the ice flakes being discharged into the chute.

The main portion of the upper bearing housing 28, above the extension 47, fills the cylinder, and the shoulder 54, between this main portion and the extension 47, lies in a plane normal to the axis of the cylinder to constitute a flat, top abutment of the chamber C, which closes the top of the cylinder. The top edge of the opening 50 is flush with this shoulder 54 and the bottom edge is at the bottom of the discharge chamber C.

In operation of the apparatus, thin layers of water in the freezing section F are frozen onto the inside wall of the cylinder 21, which are scraped off by rotation of the auger flight 42 to be moved upwardly to the chamber C. The ice layers congeal in the annulus 40, in the upper portion of the freezing section, and in the chamber, as a tubular column. As the auger rotates this column of ice, it is compressed against the shoulder 54 and the portion of the column at the opening 50 collapses and buckles out of the opening as chips or flakes of ice I, as illustrated at FIG. 7. It will be noted that this buckling action is intermittent and that the tubular ice column formed in the annulus 40 is moved upwardly above the auger and fractures erratically but usually to form large segments in the chamber C, one typical segment I being shown at FIG. 6. These segments fill the chamber, but are ejected from the opening by the aforesaid buckling action, substantially as illustrated at FIG. 7.

A number of tests demonstrated that any of the conventional, commercial ice machines available would freeze up and jam after a short period of operation if they were modified to the construction hereinabove described by the removal of their deflector means. It had been suggested that the openings could be enlarged to prevent this jamming. However, other tests demonstrated that conventional units having enlarged openings would produce slush ice. Nevertheless, the present invention is based upon the discovery that the proportions of certain components of a flake ice machine could be modified in such a manner as to produce a successfully operating flake ice machine. The most significant factor appeared to be the thickness of the cylindrical column of ice moving upwardly within the annulus 40. In the present invention, this thickness is reduced materially over that heretofore used, by providing an auger section with a comparatively large diameter 41 and a shallow flight 42. The machine operated continuously, and not only operated without jamming, but also produced a harder, drier ice, and surprisingly, with less load on the auger drive motor 37. Since constructions of this general type were recognized as eventually jamming and freezing, the factors involved were then analyzed to determine why the constructions of this present invention would not jam up and freeze, but would instead produce a harder, drier ice with less load on the auger drive motor. Tests were made to establish reasonable limitations and interrelationships of the several components which appeared significant. These components include not only the thickness T of the annulus 40, but also the height H of the opening 50, its width W and the inside diameter D of the cylinder 21.

Operative factors were also considered. By increasing the speed of the auger, it was found that the previous machines which jammed could be made to operate continuously, but that the ice produced became slush. Likewise, slush would result if the opening 50 were modified so that no compression of the ice could occur. Clearly, compression and congealing of the ice layers scraped from the cylinder by the auger was essential to the ultimate formation of ice chips suitable for commercial flake ice.

, It also became manifest that to produce commercial flake ice in any machine whatsoever, a balance was necessary between the power rating of the motor compressor 11, the effective surface of the cylindrical freezing section F, the pitch of the auger flight 42 and the speed of rotation of the auger shaft 26. Such a balance had heretofore been established in many commercial machines, and it was found unnecessary to materially alter these design features of the machines involved. In addition, such. factors as the power rating of the motor compressor 11 and the size of the cylinder 21 are determinative of the capacity of the machine. The speed of the auger can be easily adjusted to operate with any given pitch and an optimum auger speed can be easily determined by simple calibration.

It was also ascertained that a relationship existed between the height of the chamber C and the height of the freezing section F. Thus, it was determined that the height of the chamber C, as established by the height H of the outlet 50, preferably should be on the order of between 15 and 30 percent of the length of the auger within the freezing section. It was also found that considerable latitude is possible in selecting the width W of the outlet 50, providing that it is not excessively narrow, and that an operative machine could be built with an outlet width as narrow as /3 the height of the outlet and at the other extreme, an operative test machine was built with the outlet extending completely about the cylinder. Actually, the width of the opening in a commercial machine is limited by structural considerations, for the cylinder 21 is used to support the bearing housing 28 and the cut-out portion forming the opening 50 must not unduly Weaken this cylinder. In commercial units, the width may vary from approximately the height of the opening to not more than approximately two and one-half times the height of the opening. The area of the opening 50 would seem, logically, to be related to the productive capacity of the machine; however, it was found that the area of the opening, in square inches, could be varied from 0.3 to 1.0 percent of the daily capacity of the machine in pounds of ice produced.

Subsequent tests were made by varying the thickness T of the annulus 40 (that is, the width of the auger flight 42) and this factor, in conjunction with variations in the height H of the opening 50 and the diameter D of the cylinder 21, established that a simple ratio, namely could be used as a criterion for the construction of a machine which would produce better quality flake ice without jamming. When the units H, T and D were expressed in inches, it was ascertained that a conventional 600 pound ice flake machine using a deflecting device such as the indentation 55, disclosed in the Smith et al. Patent, No. 3,197,974 would have a buckling factor of 6.9 and that other machines of the same type, but of different sizes, would have similar factors. The first commercial units which eliminated the indentation 55 from the outlet chamber C and used no type of deflecting means in mum, it should be not more than approximately 20.0, if other limitations to the design were considered.

TABLE I.COMPARATIVE PROPORTIONS OF FLAKE ICE MACHINES Auger Daily Ins. Dia. Outlet Outlet H Capacity, Cylinder, Height, Width Root Lead \/5 N Pounds D H W Dia. Width '1 T 600 3. 00 1% 1% 2% 3125 6. 92 600 3. 0o 1% 1 2% .3125 9. 70 600 3. 00 1% 1% 1% .3125 10.0 660 3. 00 1% 1% 2. 437 281 10. 1 600 3. 00 1% 1% 2. 500 250 12.7 600 3. 00 1% 1% 2. 565 .227 13. 4. 600 3. 00 1% 1% 2. 625 1875 16. 2 600 3.00 1% 1% 2. 656 .170 17. 600 3.00 1% 1% 2. 625 1375 16. 2 350 2. 25 1% 1% 1. 625 0. 3125 s. 4 350 2. 25 1% 1% 1. 375 0. 1375 14. 0 225 2. 25 1% 1% 1. 625 0. 3125 7. 2 225 2. 25 1% 1% 1. 875 0. 1375 12. 0 1,500 4. 00 1% 2% 3. 475 0. 262 13. 4 2, 500 7.00 2% 5% 6.125 0. 4375 13. s

chines would operate on a test line when the machines Notes to table were n w and n, b a large percentage of e (1 Commercial 11 111 according to Patent 3,197,974 without would am when placed in the field on a commercial basls. gggg gggg gg g y3 3323 3 12 fine an er 10a d A series of test units on 600 pound capacity machines heavy jammed i field. p g were d b Increasing th auger t di t 41 t (3) Pr1or commer c1al unit; operates on test line, auger load d h k T f h 1 40 h f heavy; ammed 1n field.

ecreflse t e t 1c ness 0 t anmlus as eretq Ore (4) Test unit: operates on test line, load on auger suggests mentloned. The tests used augers having larger root diamg g g g i j g gi g g ggg fif 1m 10a 6 on an er re eters than those previously used in a machine of the 600 duced p e 8 pound size. The results of the tests demonstrated that Test i Operates e t ed e ger 9 d- (7) Test unit: operates well, selected for commercial use. whenever the buckling factor was increased 1n th1s manner (8) Test unit; auger flight too Small to operate at capacity to 12.0 or more, the machines would operate to produce 0f cylmderfl k h t Th t t (9) Present commercial unit; excellent field results. commercial a e we Wlt 0U J ge es 5 were (10) Prior commerclal unit; operates on test line; auger load continued by increasing the auger root diameter and cory;.1a 1n eld.

. d 1 h (11) Present commercial unit; good field results. resjpondlngly @creasmg the annu 11$ thlckl'less T t e (l 2) Prior commercial unit; load on auger heavy; jammed point where the space in the annulus was lnsufficrent to g gcommercialunit 00d field T It hold the ice being formed upon the walls of the cylinder es and moved upwardly by the auger. In that unit the factor was 17.5.

A new commercial 600 pound capacity ice machine was selected having a factor of 16.2, even through it approached the apparent limit. The selection was made even though the factor indicated that the proportions were close to the limit, because it was discovered that the upper limit of such a factor could be increased with machines of different size, but not greatly, without either the height H becoming in excess of 30 percent of the auger length or without the volume of the annulus being too small to hold the ice. While the machine would produce an exceptionally hard, well-formed chip of ice, an unexpected reduction of the load occurred on the motor 37 and the speed reducer 36 driving the auger. Heretofore, it was generally observed that the harder the ice chips, the greater the load on the motor and the speed reducer. Apparently, the reduction of the thickness T and the corresponding reduction of the area of the annulus 40 becomes a significant factor in reducing the total pressure upon the auger, which is caused by removing ice layers from the cylinder 21 and compressing them against the shoulder 54 to form ice chips.

The same factor i.e.

when applied to ice producing machines of the same type as herein disclosed, but of different sizes and capacities, demonstrated its reliability. For machines which would produce commercial flake ice without jamming, the factor was 12.0 for a 225 pound machine, 14.0 for a 350 pound machine, 13.4 for a 1,500 pound machine and 13.8 for a 2,500 pound machine, as set forth in the following Table I which also gives certain dimensions of the diiferent machines. To ascertain suitable limitations of the factor, check tests were made and indicated that, as a minimum, it should be at least approximately 11.0, and as a maxi- (14) Test unit: operation excellent with low auger load. (15) Present commercial unit; excellent field results.

In the field of structural design, it is known that the stability of a column under axial compressive loading, that is, its resistance to buckling under such a load, is related to the height of the column and to the thickness of its narrowest dimension. Such a relationship is commonly designated as the ratio between the height of the column and its least radius of gyration. The observed buckling of the ice segments from the outlet 50 by compressive action between the auger flight 42 and the bearing housing shoulder 54 as diagrammatically illustrated at FIG. 7, apparently involves a similar action. While the ratios set forth in the foregoing table can be considered as empirical relationships only, there is a logical basis for using such a ratio.

In considering the ice segment as a column having a height H of the outlet and a thickness T of the annulus 40, it would be suggested that a ratio H/ T would be indicative of the stability of the ice segment I, and the larger this ratio becomes, the easier the column will buckle. However, as best illustrated at FIG. 6, it also became apparent that the stability of the segment I is further influenced by the curvature of the segment which is established by the diameter of the cylinder. Accordingly, a buckling factor was found as an empirical criterion of operativeness of an ice flake machine, since it was found that the larger the factor, the easier the column I will buckle.

It is to be noted that in the foregoing disclosure, the outlet was described as being rectangular having a height H and a width W. As Table I shows, a substantial number of the tests used a square opening having the same height and the same width. Other ice machines were built for testing purposes and for production wherein the opening was made circular. Accordingly, it is to be recognized that the opening could be made not only rectangular, but also, circular, oval or rectangular with rounded corners. In

any event, any of these constructions built in operative proportions could be equated to a corresponding rectangular or square opening in which event the factor could be used to determine their operativeness.

I have now described my invention in considerable detail; however, it is obvious that others skilled in the art can devise and build alternate and equivalent constructions which are nevertheless within the spirit and scope of the invention; hence, I desire that my protection be limited, not by the constructions illustrated and described, but only by the proper scope of the appended claims.

I claim:

1. An ice chip producing machine of the type having:

(a) an end-closed, hollow cylinder of a selected inside diameter D arranged in a substantially upright mannet with the lower portion thereof constituting a freezing section and the upper portion thereof constituting a discharge chamber;

(b) a freezing means embracing the freezing section of the cylinder;

(c) a water supply means adapted to maintain water within the cylinder at a level near the top of the freezing section;

(d) a cylindrical column axially centered in the cylinder and extending through the freezing section and the discharge chamber to form an annulus about the column within the cylinder having a selected thickness T and with said column including a rotatable shaft within the freezing section;

(e) an auger flight on said shaft within the freezing section adapted to scrape off ice layers formed on the wall of the cylinder as the shaft rotates, lift the same into the discharge section and rotate the mass of ice formed by the layers as they are congealed together;

(f) a fiat, annular shoulder closing the annulus at the top of the discharge chamber;

(g) an opening in the side of the discharge chamber having a height H; and

(h) the diameter D of the shell, the height of the opening H and the thickness of the annulus T, when measured in inches, providing a factor which is greater than 11.0 and less than 20.

2. In the organization set forth in claim 1, wherein said opening is rectangular with the top of the opening being flush with and forming a lateral continuation of said annular shoulder.

3. In the organization set forth in claim 2, wherein said opening has a width exceeding one-third the height thereof.

4. In the organization set forth in claim 2, wherein said opening has a width of between approximately the height of the opening to not more than 2 /2 times the height of the opening.

5.=.In the organization set forth in claim 1, wherein the height of the discharge chamber is approximately from 15 to 30 percent of the height of the freezing section.

6. In the organization set forth in claim 1, wherein the area of said opening, in square inches, is approximately between 0.3 to 1.0 percent of the normal capacity of the unit in pounds of ice produced per day.

7. In the organization set forth in claim 1, wherein:

(a) said factor is less than 20.0;

(b) the opening has a width exceeding the height thereof;

(c) thearea of the opening, in square inches, is between 0.3 to 1.0 percent of the normal capacity of the unit in pounds of ice produced per day; and

(d) the height of the discharge chamber is from 25 to 30 percent of the height of the freezing section.

References Cited UNITED STATES PATENTS 3,162,022 12/1964 -Relph et al 62354 X 3,197,974 8/1965 Smith et al 62-354 X 3,326,014 6/1967 Fiedler 62-320 3,371,505 3/1968 Raver et al 62-320 WILLIAM E. WAYNER, Primary Examiner US. Cl. X.R. 62-354 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0. 3,501,927 March 24, 1970 Joe E. Wadsack It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, TABLE I, sixth column, line 3 thereof, "1 3/8" shou1d read 2 3/8 same table, eighth column, line 4 thereof, "10.1" should read 10.7 same table, same column, line 5 thereof, "12.7" should read 12.1

Signed and sealed this 15th day of December 1970.

( Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Ir.

Attesting Officer 

